diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 0d2f7c8a33d6..7400900de94a 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -30,8 +30,11 @@ struct hrtimer_cpu_base; * Mode arguments of xxx_hrtimer functions: */ enum hrtimer_mode { - HRTIMER_MODE_ABS, /* Time value is absolute */ - HRTIMER_MODE_REL, /* Time value is relative to now */ + HRTIMER_MODE_ABS = 0x0, /* Time value is absolute */ + HRTIMER_MODE_REL = 0x1, /* Time value is relative to now */ + HRTIMER_MODE_PINNED = 0x02, /* Timer is bound to CPU */ + HRTIMER_MODE_ABS_PINNED = 0x02, + HRTIMER_MODE_REL_PINNED = 0x03, }; /* diff --git a/include/linux/timer.h b/include/linux/timer.h index 6cdb6f3331f1..ccf882eed8f8 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -163,7 +163,10 @@ extern void add_timer_on(struct timer_list *timer, int cpu); extern int del_timer(struct timer_list * timer); extern int mod_timer(struct timer_list *timer, unsigned long expires); extern int mod_timer_pending(struct timer_list *timer, unsigned long expires); +extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires); +#define TIMER_NOT_PINNED 0 +#define TIMER_PINNED 1 /* * The jiffies value which is added to now, when there is no timer * in the timer wheel: diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index cb8a15c19583..c71bcd549241 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -193,7 +193,8 @@ struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer, * Switch the timer base to the current CPU when possible. */ static inline struct hrtimer_clock_base * -switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base) +switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base, + int pinned) { struct hrtimer_clock_base *new_base; struct hrtimer_cpu_base *new_cpu_base; @@ -907,9 +908,9 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, ret = remove_hrtimer(timer, base); /* Switch the timer base, if necessary: */ - new_base = switch_hrtimer_base(timer, base); + new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); - if (mode == HRTIMER_MODE_REL) { + if (mode & HRTIMER_MODE_REL) { tim = ktime_add_safe(tim, new_base->get_time()); /* * CONFIG_TIME_LOW_RES is a temporary way for architectures diff --git a/kernel/timer.c b/kernel/timer.c index 5c1e84beaf4a..3424dfd11d50 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -604,7 +604,8 @@ static struct tvec_base *lock_timer_base(struct timer_list *timer, } static inline int -__mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only) +__mod_timer(struct timer_list *timer, unsigned long expires, + bool pending_only, int pinned) { struct tvec_base *base, *new_base; unsigned long flags; @@ -668,7 +669,7 @@ out_unlock: */ int mod_timer_pending(struct timer_list *timer, unsigned long expires) { - return __mod_timer(timer, expires, true); + return __mod_timer(timer, expires, true, TIMER_NOT_PINNED); } EXPORT_SYMBOL(mod_timer_pending); @@ -702,10 +703,32 @@ int mod_timer(struct timer_list *timer, unsigned long expires) if (timer->expires == expires && timer_pending(timer)) return 1; - return __mod_timer(timer, expires, false); + return __mod_timer(timer, expires, false, TIMER_NOT_PINNED); } EXPORT_SYMBOL(mod_timer); +/** + * mod_timer_pinned - modify a timer's timeout + * @timer: the timer to be modified + * @expires: new timeout in jiffies + * + * mod_timer_pinned() is a way to update the expire field of an + * active timer (if the timer is inactive it will be activated) + * and not allow the timer to be migrated to a different CPU. + * + * mod_timer_pinned(timer, expires) is equivalent to: + * + * del_timer(timer); timer->expires = expires; add_timer(timer); + */ +int mod_timer_pinned(struct timer_list *timer, unsigned long expires) +{ + if (timer->expires == expires && timer_pending(timer)) + return 1; + + return __mod_timer(timer, expires, false, TIMER_PINNED); +} +EXPORT_SYMBOL(mod_timer_pinned); + /** * add_timer - start a timer * @timer: the timer to be added @@ -1356,7 +1379,7 @@ signed long __sched schedule_timeout(signed long timeout) expire = timeout + jiffies; setup_timer_on_stack(&timer, process_timeout, (unsigned long)current); - __mod_timer(&timer, expire, false); + __mod_timer(&timer, expire, false, TIMER_NOT_PINNED); schedule(); del_singleshot_timer_sync(&timer);